Display devices, such as cathode ray tube (CRT) display devices and liquid crystal display (LCD) devices, are generally characterized by a non-linear relationship between an applied input voltage and an output luminance (light intensity) for any given pixel. This relationship can be approximated by a transfer function, such as an exponential function, luminance=voltagegamma, where voltage is normalized to one. The relationship is non-linear for many display devices because exponent “gamma” is generally not equal to one.
Gamma determination and correction are important for applications involving image processing. Some image processing software applications allow a computer user to enter the gamma for the display device, so that images can be gamma corrected before display. However, the user must first know the value of the gamma. Other programs allow a user to manually adjust the gamma, but the user must still manually determine the overall gamma correction, taking into account any gamma correction that may already be included in the images to be displayed.